In vitro nematicidal activity of plant species possessing alkaloids and tannins

This study determined the most effective of three doses per plant extract on L3 nematode larvae. Seven plant species: Crinum macowanii, Gunnera perpensa, Nicotiana tabacum, Sarcostema viminale, Vernonia amygdalina, Zingiber officinale and Zizyphus mucronata, had alkaloids and tannins as bioactive principle. Ovendried leaf samples (40 g; 20 g; 10 g) of each species were extracted in 70% ethanol, and concentrated to 100 ml; constituting 4×, 2× and 1× crude extract concentration. Rectal faecal materials were collected from 10 Merino sheep and 25 Nguni goats, pooled within species and hand-mixed. Dung samples (5 g) were weighed and cultured for 12 days at 27°C. On day 13, four plates were watered, and others (4) treated with 70% ethanol to correct solvent effect on mortality. The trial had 2 (animal species) × 7 (plant species) × 3 (extract concentrations) factorial design. In each run, three plates were treated with each crude extract concentrations. L3 larvae were isolated on day 14, larval counts done, and mortality became indices of dosed anthelmintic efficacy. The study was re-run three times. Animal species (p = 0.0107) and concentration (p = 0.0005) affected efficacy; a change in crude extract concentration resulted to efficacy of 71.2 ± 2.62%, 88.0 ± 1.88% and 97.9 ± 0.91% for goats and 93.8 ± 2.62%, 96.0 ± 1.88% and 98.0 ± 0.91% for sheep. Interaction of crude extract concentration and animal species affected efficacy (p = 0.0127). Condensed *Corresponding author: Ignatius V. Nsahlai, Animal and Poultry Science, SAEES, College of Agriculture, Engineering and Sciences, PMB Campus of UKZN, 127 Rabie Saunders Building, Private bag X01, Scottsville 3209, Pietermaritzburg, Republic of South Africa E-mail: [email protected] Reviewing editor: Pedro González-Redondo, University of Seville, Spain Additional information is available at the end of the article